The present invention relates to a digitally controlled oscillator device, and a high frequency signal processing device, and particularly to a technology effective when applied to a DCO (Digitally controlled oscillator) circuit for a wireless communication system, a PLL (Phase Locked Loop) circuit including the DCO circuit, and a wireless communication high frequency signal processing device including the PLL circuit.
A system for realizing fractional capacitances using a sigma delta modulator has been shown in, for example, Non-Patent Document 1.